Manganese (IV) oxide

Raw materials

1. Dinitrogen tetroxide

2. Water

Process

One of the two chemical methods starts from natural manganese dioxide and converts it using dinitrogen tetroxide and water to manganese (II) nitrate solution. Evaporation of the water, leaves the crystalline nitrate salt. At temperatures of 400 °C, the salt decomposes, releasing N₂O₄ and leaving a residue of purified manganese dioxide. These two steps can be summarized as:

MnO₂ + N₂O₄ → Mn(NO₃)₂

Mn(NO₃)₂ → MnO₂ + N₂O₄

In the other chemical process, manganese dioxide ore is reduced by heating with oil or coal. The resulting manganese (II) oxide is dissolved in sulfuric acid and the filtered solution is treated with ammonium carbonate to precipitate MnCO₃. The carbonate is calcined in air to give a mixture of manganese(II) and manganese(IV) oxides. To complete the process, a suspension of this material in sulfuric acid is treated with sodium chlorate. Chloric acid, which forms in situ, converts any Mn(III) and Mn(II) oxides to the dioxide, releasing chlorine as a by-product.

 

Product

Manganese (IV) oxide

 

Used as

Component of dry cell batteries (called Leclanché cell or zinc-carbon batteries), oxidant in organic synthesis, pigment for body painting and cave painting (manganese dioxide was one of the earliest natural substances used by human ancestors; some of the most famous early cave paintings in Europe were executed by means of manganese dioxide)

 

Production facility

Mackay, QLD 

 

Export

Beijing, China